Index

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A

English astronomer and mathematician. At the age of 24, Adams was
the first person to predict the position of a planetary mass beyond
Uranus. After
Johann Gottfried Galle
confirmed the existence of Neptune
based on independent calculations done by Urbain Jean Joseph
Le Verrier, the two became embroiled in
a dispute over priority.

American astronomer. One of the earliest American astronomers of note,
Bond rose from poverty and overcame a lack of formal education to become
the first director of the Harvard College Observatory. At the observatory, he studied Saturn and (with William Lassell)
discovered its moon Hyperion.

C

(Aka Jean Dominique) Italian-born French astronomer. Cassini was the first
director of the Royal Observatory in Paris. He discovered four of
Saturn's moons (Tethys,
Dione, Rhea
and Iapetus) and the major gap in its rings.

Polish astronomer who advanced the
heliocentric theory that the earth
and other planets revolve around the Sun. This was highly controversial
at the time; the Ptolemaic view of the
universe, which was the prevailing theory for
more than 1000 years,
was deeply ingrained in the prevailing philosophy and religion.

F

American public official, writer, and scientist.
Franklin played a major role
in the American Revolution and helped draft the Constitution.
His numerous scientific and practical innovations include the lightning
rod, bifocal spectacles, and a stove.

G

German astronomer. Galle, along with Heinrich Louis d'Arrest, made
the first observation of Neptune based on
calculations by Urbain Jean Joseph Le Verrier.
Although Galle was the first to observe Neptune, its discovery is usually
credited to John Couch Adams (who made an earlier
calculation) and Le Verrier.

Italian astronomer and physicist. The first to use a telescope to
study the stars. Discoverer of the first moons of an extraterrestrial
body (see Galilean Moons).
Galileo was an outspoken supporter of
Copernicus's
heliocentric theory. In reaction
to Galileo, the Church declared it heresy to teach that the Earth moved
and imprisoned him. The Church clung to this position for 350 years
until Galileo was formally exonerated in 1992.

I

J

K

German astronomer and mathematician. Considered a founder of modern
astronomy, he formulated the famous three laws of planetary motion.
They comprise a quantitative formulation of
Copernicus's theory that the planets revolve
around the Sun.

L

French mathematician and astronomer. Lagrange made a number of
contributions to the study of celestial mechanics.
He showed that three bodies can lie at the apexes of an
equilateral triangle which rotates in its plane.
If one of the bodies is sufficiently massive compared with the other
two, then the triangular configuration is apparently stable.
Several examples are known in the solar system:
Such bodies are sometimes refered to as
Trojans.
The leading apex of the triangle is known as the leading Lagrange
point or L4; the trailing apex is the trailing Lagrange point or L5.

French astronomer. La Verrier's prediction of the position of an undiscovered
planet (Neptune) that caused perturbations in
the orbit of Uranus was the first to be
confirmed (by Johann Gottfried Galle). However, John Couch Adams had made a similar prediction some months
earlier.

M

(Aka Mayr) German astronomer. Marius gave
Jupiter's
"Galilean" moons
their names. He and Galileo both
claimed to have discovered them in 1610 and likely did so independently.
They became involved in a dispute over priority. Marius was also the
first to observe the Andromeda Nebula with a telescope and one of the
first to observe sunspots.

N

English mathematician and physicist. Newton invented calculus, discovered
the classical laws of motion and gravity, built the first reflecting
telescope, and demonstrated the compound nature of white light, in the process laying
the foundations of spectroscopy.

O

Dutch astronomer. Oort made major contributions to knowledge of
the structure and rotation of our galaxy. More or less as a
sideline, Oort studied comets
as well. The result of this work was a theory, now widely
accepted, that the Sun is surrounded by a distant cloud of
cometary material, now called the Oort Cloud, bits of which
are occasionally hurled into the Solar System as comets.